Interventional oncology management of noncolorectal and nonneuroendocrine hepatic metastatic disease

Introduction

The liver is a common site for metastases from various malignancies. In addition to colorectal cancers and neuroendocrine tumors, other cancers that frequently metastasize to liver include melanoma, especially uveal melanoma, breast cancer, and gastrointestinal stromal tumors (GISTs). Metastasis to the liver is common in patients with melanoma. Approximately 30% of patients with ocular melanomas develop systemic metastases, and hepatic metastases are seen in 95% of such patients. Hepatic metastases can be seen in 14%–20% of patients with metastatic cutaneous melanomas. Breast cancer has a tendency to metastasize to the liver, with approximately 25% of patients with metastatic breast carcinoma developing hepatic involvement during the course of their disease. ^, GISTs are rare but are the most common mesenchymal neoplasms of the gastrointestinal tract. The liver is the most common site of metastasis from GISTs, with a reported incidence of 55%–72% in patients with recurrence. ^,

The presence of hepatic metastases is associated with a poor prognosis and is a major cause of morbidity and mortality in patients with malignant tumors of different origins. The presence of hepatic metastases in patients with ocular melanoma is associated with median survival rates of only 6–8 months, and the 1-year survival is approximately 1015%. ^, For patients with breast cancer metastatic to the liver, median overall survival from the beginning of therapy ranges from 4 to 14 months, and the survival of untreated patients is 0.5–4 months.

Treatment options for patients with liver metastases are limited. Surgery is the only therapy that offers the possibility of cure for patients with liver metastases. Several studies have shown that surgical resection may prolong survival time of patients; however, only a small percentage of patients (10%–15% in various studies) are suitable for curative resection. Systemic chemotherapy, immunotherapy, and hormone therapy are considered mainstays in the treatment of patients with inoperable liver metastases but offer only limited benefit, and trials using systemic therapies have shown disappointing results. Systemic chemotherapy alone or in combination with immunotherapy yields response rates of less than 20% in patients with liver metastases from ocular or cutaneous melanomas, with median response durations of 5–7 months. ^{, ,} Although systemic treatment can prolong survival of patients with metastatic breast cancer, the mean survival is dismal, ranging from 4 to 17 months. ^, For GIST, imatinib is a tyrosine kinase inhibitor (TKI) that has been shown to produce a partial tumor response or tumor stabilization in 70%–85% of patients with advanced disease. ^, With imatinib therapy, the median progression-free survival is in the range of 20–24 months, and the estimated median overall survival duration exceeds 36 months. Unfortunately, approximately 15% of patients have tumors that show no response to this drug, and in a proportion of patients whose tumors do respond, resistance to the drug develops after an average of 2 years of treatment. ^, For these reasons, local or regional liver-directed treatment options that include ablative therapies and transcatheter intraarterial therapies play a major role in the management of patients with unresectable liver metastases. In this chapter, we will review the current role of these treatment options in patients with liver metastases.

Transcatheter intraarterial tumor therapies

The Society of Interventional Radiology defines “image-guided transcatheter tumor therapy” as the intravascular delivery of therapeutic agents via selective catheter placement with imaging guidance. Various agents such as chemotherapeutic agents, embolic particles, and radioactive materials can be injected via feeding vessels into tumor(s) in an attempt to achieve tumor cell death by enabling more focused delivery or by deposition of higher concentrations within the tumor.